The air leakage between a turbine vane axial face and the corresponding feature of the carrier ring is required to be limited to a minimum. The turbine vane and carrier rings are subjected to thermal and mechanical loads which induce distortion and relative movement. Therefore, leakage between a turbine vane and the corresponding feature of the carrier ring may occur.
Previously, air leakage has been minimised with direct face-to-face contact, but has been prone to an unknown rate of leakage during service.
In U.S. Pat. No. 4,815,933 a boltless turbine nozzle and a nozzle support assembly that includes a turbine nozzle mounting flange seated in a nozzle seat forming a part of the nozzle support are disclosed. A pressure actuated pliable seal is affixed to the turbine nozzle adjacent to the nozzle seat in order to provide an air seal across the completed assembly.
In EP 1 340 885 A2 a leaf seal support for a gas turbine engine nozzle vane is described. The turbine nozzle assembly includes a plurality of segments joint together to form an outer band and a plurality of segments joined together to form an inner band. At least to one airfoil is positioned between the outer and inner bands. A leaf seal is attached to each inner band segment by at least one pin member and a leaf seal is attached to each outer band segment by at least one pin member.
In U.S. Pat. No. 5,118,120 an apparatus for effecting a seal between two structural components of a turbo machine or similar device is disclosed. The apparatus comprises a leaf seal located in the space between the two components.
In U.S. Pat. No. 5,797,723 and EP 0 526 058 A1 a turbine seal is disclosed. The turbine seal includes a first arcuate segment defining a flowpath boundary between combustion gases and air and includes a radially outwardly extending rail at one end thereof. A second arcuate segment is disposed coaxially with the first segment for defining a continuation of the flowpath boundary. It has a radially extending face adjoining the rail. A leaf seal bridges the rail and the face for sealing leakage there between. A plurality of pins extended through the leaf seal for providing the mounting to the rail.
In EP 1 445 537 A2 an assembly for providing a seal at an aft end of a combustor liner for a gas turbine engine is described. The sealing assembly includes a substantially annular first sealing member positioned between an aft portion of a support member and the liner aft end so as to seat on a designated surface portion of the liner aft end. A substantially annular second sealing member is positioned between the support member aft portion and a turbine nozzle located downstream of the liner aft end so as to seat on a designated surface portion of the support member aft portion. The first and second sealing members are maintained in their respective seating positions as the support member aft portion moves radially or axially with respect to the liner aft end and radially or axially with respect to the turbine nozzle. The first and second sealing members allow for axially and radially movement of the adjacent components.
In DE 103 06 915 A1 a sealing arrangement for gas turbines is disclosed. The described sealing member comprises a number of openings through which a fluid can pass the sealing member.
In WO 2005/033558 A1 a seal which comprises a first and a second component is disclosed. The seal is applied to a combustion chamber for a gas turbine. It comprises a spring load which provides a seal also in the case of vibrations in the combustion chamber. The seal is further applied to the sealing between adjacent stationary blade platforms in gas turbines. The seal comprises a number of openings for leading a fluid through the seal.
U.S. Pat. No. 5,343,694 a gas turbine nozzle including a plurality of nozzle segments having a pair of nozzle vanes supported by inner and outer shroud segments is disclosed. The outer shroud segment includes a generally axially extending platform with a circumferentially extending seal member attached to the upstream end thereof to seal with the combustor liner flange against the leakage there between. Moreover, a radially extending circumferential projection is attached to the downstream end of the platform for providing an engagement surface for a W seal to prevent leakage between the outer rotor casing and the shroud segment.
In WO 2009/085949 A1 and US 2009/0169370 A1 a turbine nozzle segment including a band having a plurality of tabs is disclosed. An airfoil extending from the band and a support structure attached to the tabs is described. The support structure has a plurality of biasing structures.
In US 2009/0074562 A1 a turbine nozzle guide vane with passages leading from a hollow core to respective seal strip slots to deliver cooling air to abutment faces on each end of the vane is disclosed.
In EP 2 180 143 A1 a gas turbine nozzle arrangement is disclosed. It comprises at least one seal strip which is present between a radially outer surface of a carrier ring section and inner surface of an inner platform and comprises openings for allowing cooling fluid to flow through the seal strip.
The document EP 1 296 023 A1 discloses a devise for holding strip sealing gaskets on a turbo machine nozzle.
The document WO 2009/158554 A2 describes a seal for containment of fluids or gases during high temperature applications.
In U.S. Pat. No. 5,118,120 entitled “leaf seal” an apparatus for effecting a seal between two structure components of a turbo machine is taught, comprising a leaf seal located in the space between the two components and a spring which continuously biases the leaf seal into a sealing position against the components regardless of the pressure differential across the leaf seal.